We propose to study the benefit of oral antifibrinolytic therapy with tranexamic acid in thrombocytopenic patients with platelet counts of less than 20,000/microliter. These patients are at significant risk for bleeding, and may suffer epistaxis, oral, GI, GU, or CNS hemorrhage. Currently, these patients are treated with platelet transfusions in order to minimize this bleeding risk. However, such transfusions are not without morbidity: hepatitis, alloimmunization, allergic and febrile transfusion reactions, and volume overload may all result from platelet transfusions. It also is logistically difficult to give platelets to outpatients, and in many areas of the U.S. platelets for transfusion are not available. Moreover, such transfusions are extensive, and patients requiring large numbers of platelets may tax the ability of procurement programs to provide them. Antifibrinolytic therapy has been shown to be of proven efficacy in some clinical situations associated with bleeding. We hope to establish that thrombocytopenic patients will benefit from antifibrinolytic therapy by having fewer bleeding episodes and requiring fewer transfusions.